Suppressing Beam Squint Effect For Near-Field Wideband Communication Through Movable Antennas

TL;DR

This paper proposes a novel method using movable antennas to mitigate beam squint effects in near-field wideband MISO systems, improving beamforming gain across the spectrum.

Contribution

It introduces a new algorithm leveraging SGDA to optimize antenna positions, effectively reducing beam squint in near-field wideband communications.

Findings

Algorithms effectively mitigate beam squint.

Movable antennas enhance wideband beamforming performance.

Numerical results confirm the proposed method's effectiveness.

Abstract

In this correspondence, we study deploying movable antenna (MA) array in a wideband multiple-input-single-output (MISO) communication system, where near-field (NF) channel model is considered. To alleviate beam squint effect, we propose to maximize the minimum analog beamforming gain across the entire wideband spectrum by appropriately adjusting MAs' positions, which is a highly challenging task. By introducing a slack variable and adopting the cutting-the-edge smoothed-gradient-descent-ascent (SGDA) method, we develop algorithms to resolve the aforementioned challenge. Numerical results verify the effectiveness of our proposed algorithms and demonstrate the benefit of utilizing MA array to mitigate beam squint effect in NF wideband system.